As a dye for dyeing or textile printing a fiber material, for example, azo compounds having a vinyl sulfone reactive group have hitherto been known (e.g. JP-A-50-178, JP-A-63-77947, JP-A-6-287463).
However, even when these azo compounds are used for dyeing or textile printing fiber materials such as natural or regenerated cellulose fiber, they do not satisfy the reproducibility, levelness, color value, build-up properties, chlorine atom treated water fastness, tap water chlorine atom fastness, light fastness, perspiration light fastness, etc. Therefore, it has been desired to develop a dye which satisfies these performances. Also, it has strongly been desired to develop a dye which causes little discoloration at the time of various processing treatments; affords a dyed or textile-printed product having excellent storage stability; and exhibits high effective dyeing ratio capable of reducing a coloration of dyeing waste water with the recent increase of interest about environmental problems.
Under these circumstances, the present inventors have studied intensively for the purpose of obtaining a dye which is excellent in reproducibility and levelness, and exhibits high build up properties, high color value and high effective dyeing ratio in a dyeing and textile-printing treatment of fiber materials; and affords a dyed or textile-printed product which is excellent in fastnesses, particularly chlorine atom treated water fastness, tap water chlorine atom fastness, light fastness and perspiration light fastness, causes little discoloration at the time of various processing treatments, and exhibits excellent storage stability. As a result, it has been found that a specific polyazo compound or a salt thereof has desired performances. Thus, the present invention has been accomplished.